Phosphorizing apparatus



April7, 1953 J. R. WYATT PHOSPHORIZING APPARATUS 4 Sheets-Sheet 1 Filed May 16, 1947 NH @H l INVENTOR ATTORNEYS April 7, 1953 J. R. WYATI' FHOSPHORIZING APPARATUS 4 Sheets-Sheet 2 Filed May 16. 1947 INVENTOR J. R. WYATT PHOSPHORIZING APPARATUS April 7, 1953 4 Sheets-Sheet 3 Filed May 16. 1947 INVENTOR uid which prevents combust-i Further p ses ap ea xi h "and in theclaims.

Patented Apr. 7, 1953 2,634,027 PHOSPHQRIZING APPARATUS Jame R- Wyat Hay r wn, Pa, assignor to The iax M a Com n de ia Pa a poration of Bennsylvania' Q pplication'May 16, 1947, Serial N 0. 748,637

:6 C aimsl phorizing, and especially for making phosphor copper.

Divisional applications of the'present application have been filed, Serial No. 80,081 for Phosphorizing Process, Serial No. 80,082 for Phosphorizing Apparatus and Serial No. 80,088 for Phosphorizing Apparatus, all filed March 'l, 1949.

A purpose of my invention is to reduce the accident rate and reduce or eliminate the health hazard in-phosphorizing.

A further purpose is to eliminate the smoke nuisance incident to "present methods of hosphorizing.

A further purpose isto increase the yield and also increase therate of phosphorus absorption by molten metalat high :yield and permit continuous operation.

' A further purposeis to-avoid the necessity of copper coating phosphorus before-phosphorizing.

A further purposeis'toavoid the-difficulty and inconvenience due'tothe'formation of red phosphorus.

A further purpose is-to more accurately control the ultimate phosphorus content of the phosphor copper and more accurately regulate the rate of phosphorizing.

A further purpose is to melt white'phosphorus remoteffromits point of-dispensing, sothat possible leakage incident to charging phosphorus to be melted will not create ya hazard at'the point of dispensing.

A further purpose is to-supplyheat formelting white phosphorus through an inertprotective liqon of "the phosphorus.

Av further purpose is to pum from a melting pool to a. dispensing pool of molten phosphorus by pressure 0111811 inert liquid floating" n the phosphorus of the meltingpooland to dispense by pressure on aninert liquid floating on the dispensing pool, and desirably'by introducin a measured quantity of inert liquid into a confined space containing the'dispensing pool. I

A further purpose is to; maintain molten phosphorus under temperaturecontrol which wi-ll prevent formation of red'phosphorus frornthe time it leaves a dispensing pool until it-rea'ches the high temperature zon of the molten metal.

1 A further purposeisto obtain the measured quantity of inert liquid'fordispensing from an inert liquid column above the dispensing pool,

specification '1 have chosen to "illustrate myinventionby 2 showing a few only of the many possible embodiments, choosingthe forms shownfrom the standpoints of convenience in illustration, satisfactory operation, and clear demonstration of the'principles involved.

Figure l is a diagrammatic Vertical section Of .One ,phosphorizing apparatus embodying my invention.

Figure 2'is a topplan view of Figure 1.

Figure 3 isadiagrammatic vertical section of a preferred phosphorizing apparatus which embodies a modification of the form of Figures 1 and 2.

Figure 1.4 is an enlarged central vertical section through my preferred phosphorizing nozzle.

Figure 4 is a fragmentary view correspondin to Figure 4, showing a modification.

-Figure'5is a section on the lim t- 5 01 Fisure 4.

Describing in illustration but not in limitation,

and referringto the drawings:

. ployed in the metallurgical industry, the most widely known :being phosphor copper, which is used as a, deoxidizingagent, and in the manufacture .-.of phosphorus containing alloys such as Phosphor bronze.

Phosphorus is: likely to be a very. hazardous material to handle, particularly because it is inflammable, it is very toxic, particularly in vapor form,

and the effects are cumulative in the humanbody. The handling of phosphorus is complicated by the fact that it existsin allotropic modifications.

For example, whitephosphorus is quit inflam- -mab1e in airand melts at about 111 F, ;At from 440 to 480 white phosphorus is co verted to red phosphorus, which, is-more inert and of gher 'meltingcpoint; Thepractice in making phosphor copper has been to coat .white, phosphorus with a protective layerof copper and to charge the copper coated cakes .of phosphorus into the molten copper, preferably below. thesurface .of the bath. :This has been a very'hazardous occupation, as it is essentialthat the operator must not breathe phosphorus vapor." Furthermore ,it has been 2 time-consuming-and expensive both "from a labor standpoint because of the time involved, and

from a furnace standpoint. because of the delay in the furnace cycle. The loss in phosphorus has been very considerable, A addin to the expense, and since much-of the phosphorus loss. creates phosphorus pentoxide smoke, the smoke nuisance 'has'been serious.

" Various efiorts has been made i to rover-come these and related difiiculties. Demler U. S. Patent No. 1,287,653 and Nicholson U. S. Patent No. 1,425,679 distill phosphorus from a retort and conduct the vapor to the point of phosphorizing. Applicant has experimented with this technique and has designed an apparatus of this character. The problem, however, is not simple as in the case of ordinary materials which do not exhibit allotropic change. It has been found that almost inevitably some part of the retort or connections will operate at a temperature favoring the formation of red phosphorus, and at such locations red phosphorus accumulates rapidly, clogging the apparatus and necessitating frequent shut-downs for cleaning. Since the apparatus is initially thoroughly filled with phosphorus vapor, and white phosphorus is retained in many parts of the equipment, cleaning is a very hazardous occupation, and it becomes a question whether it is not safer to use the well known practice of charsing copper coated cakes of white phosphorus. Added to this is the certainty that any leakage of phosphorus vapor from the retort may have fatal consequences to workmen.

Burns U. S. Patent No. 2,164,228 applies molten phosphorus to metal by an apparatus which is essentially a dropping funnel suspended above the molten metal bath, in which phosphorus is melted below water, and from which it is dropped under valve control into a nozzle beneath the surface of the metal. This presents the difiiculty of exposing the entire mechanism to the heat of the molten metal bath, and hazarding difiiculty or danger through leakage, since the dropping funnel must be opened periodically to introduce cakes of white phosphorus.

In accordance with the present invention, the difiiculties of the various prior art processes are overcome without appreciable increase in the cost of the operation.

It has been found that by the present invention, the loss in phosphorizing copper can be cut to 20% of the loss presently encountered in charging copper coated cakes of white phosphorus. At the same time the smoke nuisance is largely eliminated. Handling of the phosphorus by the individual worker can be entirely eliminated. .Ihe step of copper coating the phosphorus is rendered unnecessary. The process is made continuous, with very excellent control over both the total amount of phosphorus alloyed, and the rate of alloying. The speed of alloying can be increased beyond that at present practiced.

The hazard through accident or impairment of health is practically eliminated, both from handling of phosphorus and from phosphorus vapor. The dispensing tank can be tightly closed and need not be opened at any stage of the operation, so that the danger of leakage of phosphorus vapor is greatly reduced. Labor cost is cut down.

In accordance with my invention, the formation of red phosphorus does not occur, andhazardous and troublesome cleaning to remove accumulations of red phosphorus from the apparatus is not necessary. The molten phosphorus is kept under temperature control from the dispensing pool to the high temperature zone of the molten metal, thus maintaining a temperature which will prevent formation of red phosphorus.

Considering first the form of Figures 1 and 2, I

provide a tank 20 conveniently open at the top, and made from any suitable material such as steel or stainless steel. The tank is filled to a convenient height with inert liquid 2 i, suit/ably water. As the purpose of the inert liquid is partially heat transfer, partially prevention of combustion of white phosphorus, and partially displacement of phosphorus, it will be evident that water is the preferred inert liquid, but that other suitable inert liquids may be used, as, for example, phosphoric acid or, where the fire hazard can be controlled, a mineral oil such as kerosene (kerosene is not recommended because of the fire hazard). The tank is heated by any suitable means, such as gas burner 22 having a gas connection 23, an air inlet 24 and a combustion gas flue 25 suitably passing up through the tank 23.

Within the tank 25, two pools of molten phosphorus 26 and 21 are located, each having upon its surface a poolof inert liquid 28 or 29, which will be desirably identical with the inert liquid 2 i.

g The pool of molten phosphorus 23 and of inert liquid 28 is contained within 9. tank 30, and the pool of molten phosphorus 27 and of inert liquid 29 is contained within the tank 3|. Both tanks are suitably of steel or stainless steel, in heat transfer relation with the tank 20, and the pool of inert liquid 2| contained therein. The tanks 30 and 3! may suitably be supported on a frame 32 in the bottom of the tank 28.

Access to the interior of the tank 31 is not necessary in the process, and one of the advantages of the process is the fact that the head 33 of tank 3| can be permanently gasketed or welded on at 34 to prevent the possibility of leakage, and. particularly to prevent the possibility of any escape of phosphorus vapor, if vapors should be carried back from the discharge nozzle.

On the other hand, the head 35 of tank 30 is removably bolted and gasketed at 35, so that it can be readily removed to introduce white phosphorus to be melted in the pool 26.

The melting tank 30 is connected through its head 35 to a source of inert liquid under pressure. This is conveniently a pump 31 driven by a motor 38 having inlet at 39 from the pool 21 and discharging at 40 through flexible connections controlled by valve ll, the discharge passing directly to the pool of inert liquid 28.

The head 35 of tank 30 is also conveniently provided with a safety valve 32.

To permit transfer of molten phosphorus from pool 26 to pool 21, a connection 43 extends to near the bottom of pool 28 in tank 30, through union 44 and valve 45 to pool 23 above pool 21 in tank 3|.

Tank 3| is equipped with mechanism to introduce a measured quantity of inert liquid into pool 29. This is accomplished by pump 43 driven by motor 41 having inlet at 48 (desirably connected to the pool 21, but broken away to avoid complication in the drawing) and discharging through connection 49, relief valve 50, pressure gauge 5|, flow meter 52 (rotating type), and flow meter 53 (variable orifice type), check valve 54, and valve 55 to the head 33 of tank 3!. An overflow valve to permit discharge of inert liquid from pool 29 in tank 3| is provided at 53.

As a means of checking the level of molten phosphorus in tank 3 l, float 5'! is provided in float column 58 extending to the bottom of the molten phosphorus, open at the bottom and closed at the sides, and having indicator stem 59 in cover glass 60, closed at the top. The combined weight of the float and indicator is chosen so that it is less than the weight of the phosphorus displaced by the parts submerged in phosphorus, but greater than the weight of the inert liquid displaced by the total submerged parts if they were in inert liquid. All of this of course presupposes the weight of the molten phosphorus and inert liquid at the parnsets-"7' tieular temperature at which they are held. Thus the float will float on molten phosphorus but will in inert liquid, the inert liquid being lighter than the molten phosphorus, and the position of the float will always indicate the top of the pool '21.,

From the dispensing pool 21, discharge is ac complished to a discharge nozzle 6| below the level of the molten metal 62 in a suitable furnace 63 by a connection 64 extending to the bottom of the pool 21. It is important that the molten phosphorus should not solidify in the discharge connection and should not get hot enough to form liedphosphorus there, and therefore the discharge connection is jacketed, preferably by ine liq ita l w t raw fii the b th 2.1;. at the preferred temperature of about 180 F. f Ihi s is accomplished by a pump 65 driven 'by rnotor 65' which has inlet connections 66 to the pool 21 and discharges at 61 to water jacket 68 surrounding one portion of the discharge connection, then flowing through connection 69 and through water jacket 10 surrounding a bend 1| in the flexible connection. Discharge is through a conduit 12 which returns to the pool 2|. The

inert liquid connections 61 and 12 are suitably made, flexible, since the connection 64 for flow of molten phosphorus to the nozzle is made flexi-r ble by a universal type joint 13. Discharge of molten phosphorus to the nozzle 6| is controlled by discharge valve 14, which is conveniently located between the heating jackets 68 and 19.

In Figure 3 I illustrate a variation in respect both to the nozzle construction, as later explained, and as to the arrangement for measuring inert liquid to be introduced into the dispensing pool.

A water column 15 is provided suitably in the form of a closed tank preferably extending to a height substantially above the pools 28 and 29. The water column 15 is provided with a liquid level gauge 16, suitably of the sight glass type familiar in boilers. Inert liquid inlet is provided to the inert liquid column by a connection 11 from pump 31 controlled by valve 18 and conveniently entering near the closed top of the inert liquid column.

Discharge of inert liquid from a point conveniently located below the gauge on the inert liquid column'is provided by a connection 19 controlled by valve 89 and having a flow meter 8 I.

In order to force the inert liquid from the inert :liquid column into the pool 29, I provide a source of gas under pressure, suitably an air compressor 82 driven by motor 83 and discharging compressed air through connection 84 and valve 85-to the top of the inert liquid in the inert liquid column 15. u r

In Figures 1 and 2, the nozzle is of conical form as indicated at 86, and has a conical interior bore :81 extending from end to end vertically and communicating with connection 64. This nozzle is made of suitable refractory material, preferably graphite.

. InFigures 3, 4 and 5 I illustrate a variant form of nozzle GI which is suitably tubular in exteriorv dimension and contains an interior conical bore 181. The nozzle 6| ismost conveniently manufactured by boring out a graphite electric furnace electrode or other similar carbon refractory cylinder. The nozzle is mounted in a metallic nozzleholder 83 having a side opening for the connection 64, aclosure cap89, a distribution ch be Bi -ends is har o ifice a1 immedi- "a telyabove the bore 81. The nozzle holder has a tubular socket 92' which reserves the end of the nozzle BI', makingyapor-tight seal by a Steel bellows 93 between the end of the nozzle and the base of the socket and a packing 94 clamped against theside" of nozzle by a packing ring 9s suitably threaded on the nozzle holder. The nozzle is held in the holder and drawn up tight against the packing 93 by bolts 96 acting between radial lugs 91 on the holder and a split ring 98 attached in a recess 99 on the nozzle. v 7

At intervals around the circumference of the nozzle above the bottom opening lflll' of the bore, jet openings I01. are provided extending radially and preferably downwardly an angle, as best een in Figure 4. It has been fdllhd in practice that phosphorus didps thrdllgh the orifice 9'],

is expelled in jets" through the jet openings m, extending for considerable distances: in the molten metal surrounding the orif ce, and thus being very effectively asserted; When the volume of vapor is too great to discharge through the jet openings l lll, it is, of 'soursarree to discharge through the end opening I00, but the penetration into the molten bath is likely to be less extensive andmore dependence is placed upon diffusion and stirring of the bath to obtain uniformity of phosphorizing, H

It has been found in practice ,with the jet of the type of Figures 3, 4 and5 and a bath of adequate size to maintain thejet preferably a foot or more below the bath surface, that there is noserious danger of phosphorus vapor not being absorbed by the molten copper. As an additional protection, however, against this contingency it is desirable to maintain carbon on the bath at I92, and to maintain ran-adequate supply of air so that the conditions will be oxidizing above the carbon (charcoal), and any possible phosphorus vapor discharging would be oxidized to phosphorus pentoxide. This feature is precautionary, however, as the small amount of smoke and the high yield indicate that little phosphorus is lost.

As the nozzle is used, theholes llll may enlarge and the jet effect he lost, the vapor passing upward along the outside surface of the nozzle, without adequate contact with the metal. In Figures 4* I illustrate an annular enlargement, ring or shell I05 around the nozzle above the openings I01, which assures deflection of any rising vapor outwardly, and adequate contact with the molten metal.

In making phosphor copper the operation is usually continued until about'14% has been combined, the percentage being somewhat critical as in the case of higher phosphorus contents the alloy may take fire.

In operation, the apparatus is set up as shown, the gas or other fuel burner being maintained so that the inert liquid (water) will preferably be at a temperature of about to F. in the pool 2!.

With all valves closed, the head 35 is removed from tank 39, and solid white phosphorus to be melted is introducedinto the tank- 30 to join the pool 26. Where the white phosphorusis inthe form of cakes, these may simply be dropped through the inert liquid of thepool '28 into the pool 26. It is preferred, however, to insert a drum of phosphorus bottom up with the head removed as shownat I03 in Figure 1, using chain grips l 04, so that the drum may discharge by the suitably gasketed at 36 on the tank 30. While it dispensing pool 21. Y y

immersedw'ell below the level of the molten metal is desirable to have thisgasketing tight, no harm willbe done if there. is a slight leakage as it is impossible for phosphorus vapor from the nozzle to flow back into tank 30 during phosphorizing, since the valve 45 is kept closed at such times. The only harm done by leakage at the gasket 36 is that some pressure will be lost in pumping molten phosphorus into the dispensing pool.

If any mistake is made in charging by which pieces or fragments of phosphorus drop into the pool 21, no serious harm is done as the pool 2| provides protection from fire and the phosphorus will simply remain at the bottom of the tank 253, from which it may be removed.

In order to transfer phosphorus from pool 28 to pool 21, valve 45 in the connection 43 between the tanks 35 and 3| is opened, overflow valve 56 'ontankBl is opened, and with pump 31 operating, valve 41 isopened to apply inert liquid pressure to pool 28 onpool 26 in tank as. This results in forcing molten phosphorus from melting pool 26 through connectionv 43 into tank 3i, where it drops into and forms part of dispensing pool '27. The level of molten phosphorus in pool 21 is shown at all times by float 5'? on indicator 59, themolten phosphorus oi the pool communicating with the float through the open bottom of column 50. As soon'as sufficient phosphorus has arrived in pool 27, valves 4|, 45 and 56 are closed and pump 31 is turned off.

In order to 'phosphorize, using the form of Figures 1 and 2, the nozzle 8! is inserted well below' the level of the molten metal in furnace 63, manipulating the nozzle by means of universal joint 13. Pump 64 is started so that the exposed portions of connection 6d are well heated by the warm inert liquid from pool 2 I. To begin phosphorizing, pump 46 is started and valve 55 is opened to permit inert liquid to enter pool 29, and discharge valve '54 is opened to permit phosphorus to be displaced from pool 2? and discharged through the nozzle. Valves 55 and 16 'are adjusted to obtain the desired flow as shown by fiow meters 52 and 53. The quantity of phosphorus discharged by the nozzle can be determined, since it is equal to the quantity of inert liquid passing through the flow meters 52 and 53.' The change in level of the float 51 can be used as a check, and to be sure that the pool 21 is not completely depleted.

The phosphorus dropping through the bore of the nozzle is very rapidly vaporized in the nozzle and discharged as vapor into the molten metal. In most cases, molten phosphorus never actually reaches the surface of the molten metal, but if it does it is very rapidly vaporized and the vapor carried into the molten metal. Where a nozzle of the type of Figures 3, 4 and 5 is used, this vaporization results in jets discharging through the jet openings lfll into the molten metal.

In the form of Figure 3, the pool 26 is filled as above described. With all other valves closed, the air bleed 85' from the inert liquid column is opened. Pump 31 is started, and valve '18 opened to introduce inert liquid through connection E1 to a suitable level at the-upper part of the gauge, if the inert liquid level be unduly low. Valves 18 and 84' are then closed. Pump 82 is started and valve 8.; opened to apply. air pressure to the top of the inert liquid column, tending to force the inert liquid out of the column. Valve 80 is opened to connect the bottom of the inert liquid column with the pool 29 above the phosphorus The nozzle 51' is suitably 62 as shown in Figure 3, and the dispensing valve 1:1. opened. Molten phosphorus from the pool 21 is now displaced through the connection 64 which is of course suitably heated by the heating jacket 88 supplied with heated inert liquid through pump 65 as previously explained. The rate of dispensing of molten phosphorus can be gauged by the fiow meter 8i, and the total quantity of phosphorus discharge can be gauged by the difference in level of inert liquid on the gauge 16, which will correspond with the volume of phosphorus dispensed. This method of gauging is preferred because it is more accurate than the flow meter method.

It will be evident that by the present invention I am able to introduce phosphorus to a molten metal bath without handling of the material from the time it is first charged for melting, and even this can be done by handling a drum and without individual handling of cakes. It will further be evident that at the time that dispensing takes place, the connection to the melting pool through the valve 55 is closed, so that the danger through leakage of the melting tank is avoided. It will also be evident that during dispensing, the molten phosphorus in the dispensing pool is protected not only by the pool of inert liquid covering it, but also by the inert liquid being supplied from the pump or from the inert liquid column.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the apparatus shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a phosphorizing apparatus, a first closed tank, a body of phosphorus in the first closed tank, a body of inert liquid in the first closed tank above the phosphorus, a second closed tank, a body of molten phosphorus in the second closed tank, a body of inert liquid in the second closed tank above the body of molten phosphorus, heating means for melting phosphorus in the first closed tank, means permitting introduction of solid phosphorus into the first closed tank, a valve connection from the body of phosphorus in the first closed tank to the body of phosphorus in the second closed tank, means for applying pressure to the first tank upon the closed tank and connected therewith, a gage showing the level in the inert liquid column, and means for forcing inert liquid from the column into the second closed tank.

2. In a phosphorizlng apparatus, a first closed tank, a body of phosphorus in the first closed tank, a body of inert liquid in the first closed tank above the phosphorus therein, a second closed tank, a body of molten phosphorus in the second closed tank, a body of inert liquid in the second closed tank above the molten phosphorus therein, heating means for melting phosphorus in the first closed tank, means permitting introduction of solid phosphorus into the first closed tank, a valve connection from the phosphorus in the first closed tank to the phosphorus in the second closed tank, means for applying pressure to the first tank above the inert liquid therein to force molten phosphorus through the connection into the second tank, a discharge connection from the second tank, means for maintaining the discharge connection from the second tank at a temperature between the melting point of white phosphorus and the temperature which favors formation of red phosphorus, a refractory nozzle on the discharge connection and means for forcing a measured quantity of inert liquid into the second tank.

3. In a phosphorizing apparatus, a first tank, a body of inert liquid in the first tank, a second tank within the first tank surrounded by the body of inert liquid, a body of phosphorus in the second tank, a body of inert liquid in the second tank on top of the phosphorus, there being a removable head on the second tank to permit insertion of solid phosphorus, a third tank within the first tank surrounded by the inert liquid therein, a body of molten phosphorus in the third tank, a body of inert liquid above the molten phosphorus in the third tank, means for heating the first tank, a connection from the bottom of the second tank to the third tank, a valve controlling this connection, means for applying pressure to the body of inert liquid in the second tank to pump molten phosphorus into the third tank, a discharge nozzle, a connection from the bottom of the third tank to the discharge nozzle, and means for pumping inert liquid into the third tank to force molten phosphorus out the discharge nozzle.

4. In a phosphorizing apparatus, a first tank, body of inert liquid in the first tank, a second tank within the body of inert liquid in the first tank and having a removable head to permit insertion of solid phosphorus, a body of phosphorus in the second tank, a body of inert liquid on the phosphorus in the second tank, a third tank within the inert liquid in the first tank, a body of molten phosphorus in the third tank, a body of inert liquid on the molten phosphorus in the third tank, means for heating the first tank, a connection from the bottom of the second tank to the body of molten phosphorus in the third tank, a valve controlling this connection, means for applying pressure to the inert liquid in the second tank to pump molten phosphorus into the third tank, a discharge nozzle, a connection from the bottom of the third tank to the discharge nozzle, and means for measuring and for pumping a measured quantity of inert liquid into the third tank to force molten phosphorus outthe discharge nozzle.

5. In a phosphorizing apparatus, a first tank, a body of inert liquid in the first tank, a second tank within the inert liquid in the first tank and having a removable head to permit insertion of solid phosphorus, a body of phosphorus in the second tank, a body of inert liquid on the phosphorus in the second tank, a third tank, a body of molten phosphorus in the third tank, a body of inert liquid on the molten phosphorus in the third tank, means for heating the first tank, a connection from the bottom of the second tank to the molten phosphorus in the third tank, a valve controlling this connection, means for applying pressure to the inert liquid in the second tank to pump molten phosphorus into the third tank, a discharge nozzle, a connection from the bottom of the third tank to the discharge nozzle, an inert liquid column, a connection from the bottom of the liquid column to the inert liquid in the third tank, a gage for the liquid column and means for pumping inert liquid from the liquid column into the third tank for forcing molten phosphorus out the discharge nozzle.

6. In a phosphorizing apparatus, a first tank, a body of inert liquid in the first tank, a second tank within the inert liquid in the first tank, and having a removable head to permit insertion of solid phosphorus, a body of phosphorus in the second tank, a body of inert liquid on the phosphorus in the second tank, a third tank in the inert liquid in the first tank, a body of molten phosphorus in the third tank, a body of inert liquid on the molten phosphorus in the third tank, means for heating the first tank, a connection from the bottom of the second tank to the third tank, a valve controlling this connection, means for applying pressure to the inert liquid in the second tank to pump molten phosphorus into the third tank, a discharge nozzle, a flexible connection from the bottom of the third tank to the discharge nozzle, means for heating the flexible connection to a temperature between the melting point of white phosphorus and the temperature which favors formation of red phosphorus, and means for pumping a measured quantity of inert liquid into the. third tank to force molten phosphorus through the flexible connection and out the discharge nozzle.

JAMES R. WYATT.

REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 143,810 Cowell Oct. 21, 1873 1,173,117 Obermann Feb. 22, 1916 1,657,532 Farr Jan. 31, 1928 1,837,339 Schlick Dec. 22, 1931 2,079,898 Burchenal May 11, 1937 2,158,517 McParlin May 16, 1939 2,164,228 Burns June 27, 1939 2,191,337 Clark Feb. 20, 1940 2,246,594 Kinsella June 24, 1941 OTHER REFERENCES Transactions of the Electrochemical Society, vol. 81 (1942), pp. 97-102. 

6. IN A PHOSPHORIZING APPARATUS, A FIRST TANK, A BODY OF INERT LIQUID IN THE FIRST TANK, A SECOND TANK WITHIN THE INERT LIQUID IN THE FIRST TANK, AND HAVING A REMOVABLE HEAD TO PERMIT INSERTION OF SOLID PHOSPHORUS, A BODY OF PHOSPHORUS IN THE SECOND TANK, A BODY OF INERT LIQUID ON THE PHOSPHORUS IN THE SECOND TANK, A THIRD TANK IN THE INERT LIQUID IN THE FIRST TANK, A BODY OF MOLTEN PHOSPHORUS IN THE THIRD TANK, A BODY OF INERT LIQUID ON THE MOLTEN PHOSPHORUS IN THE THIRD TANK, MEANS FOR HEATING THE FIRST TANK, A CONNECTION FROM THE BOTTOM OF THE SECOND TANK TO THE THIRD TANK, A VALVE CONTROLLING THIS CONNECTION, MEANS FOR APPLYING PRESSURE TO THE INERT LIQUID IN THE SECOND TANK TO PUMP MOLTEN PHOSPHORUS INTO THE THIRD TANK, A DISCHARGE NOZZLE, A FLEXIBLE CONNECTION FROM THE BOTTOM OF THE THIRD TANK TO THE DISCHARGE NOZZLE, MEANS FOR HEATING THE FLEXIBLE CONNECTION TO A TEMPERATURE BETWEEN THE MELTING POINT OF WHITE PHOSPHORUS AND THE TEMPERATURE WHICH FAVORS FORMATION OF RED PHOSPHORUS, AND MEANS FOR PUMPING A MEASURED QUANTITY OF INERT LIQUID INTO THE THIRD TANK TO FORCE MOLTEN PHOSPHORUS THROUGH THE FLEXIBLE CONNECTION AND OUT THE DISCHARGE NOZZLE. 